A Demand to Expand

Every day, about 3,300 tons of post-source separated municipal solid waste is collected from Los Angeles city residents. While most is landfilled, about 1 percent is turned into electricity at the Southeast Resource Recovery Facility in Long Beach, Calif., a 36-megawatt waste-to-energy (WtE) plant operated by Covanta Energy Corp.

In order to further reduce the amount of waste landfilled and keep up with increasing energy demands, Los Angeles is planning to build an additional WtE plant. It is part of a broader, long-term plan the city has adopted, calling for it to construct six more WtE plants in each of its waste sheds over the next 20 years.

Although it’s still early in the planning process, one item can be checked off the city’s to-do list, and that is selecting a technology provider for the first facility. The city recently announced it has begun contract negotiations with Rye, N.Y.-based Green Conversion Systems to design and build the plant.The decision was made after a great deal of research, as the city has been conducting an extensive search to evaluate different waste conversion technologies for the past four years, reviewing 13 different proposals. Evaluated vendors have offered a variety of solutions including pyrolysis, gasification, plasma arc, anaerobic digestion and Green Conversion Systems’ Advanced Thermal Recycling (ATR) system.

Based on the GCS technology, the new facility would be capable of processing nearly 1,100 tons per day of post-recycled residential waste using a two-step system of preprocessing and advanced thermal recycling. During preprocessing, all waste entering the facility is sorted to remove recyclable materials such as plastics, metals and paper. The nonrecyclable waste is then sent to the ATR system, which converts 99 percent of it into electricity—enough to power more than 6,000 homes—and marketable byproducts.

The ATR technology has been commonly used in Europe for the past two decades. During the summer of 2008, a Los Angeles city delegation visited several reference sites in Europe to evaluate and determine the applicability of the technology, according to the L.A. Department of Public Works.

GCS will now come back to the city with a proposal, says L.A. Department of Public Works Public Affairs Director Cora Jackson-Fossett. A site for the facility has not yet been determined, she adds, and likely won’t be for a year or two. Where it will be located will be based on an external community input process. “We have a very involved, environmentally conscious community here,” she says.